Filter cassette



FIG. 1 is a front perspective view of a filter cassette, showing our new design;

FIG. 2 is a rear perspective thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof. 

The ornamental design for a filter cassette, as shown. 